Note: This post is tested/valid as of Oct 2023 for TradeStation 10.x. It may continue to be valid for future TradeStation releases as well.
When TradeStation is closed by choosing the File-Exit menu option, the visible programs (desktops, workspaces) are closed. However, some of the background processes continue to run. If you wanted to close all those processes, you could run this BAT file aptly named KillTS.BAT.
Once the KillTS.BAT file is run, it closes all TradeStation background processes.
Here is the link to get the KillTS.BAT file.